Re: CMS 20 MEG SCSI HD question

[Phil Beesley <pb14@le.ac.uk>]

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In article <7phv9u$plu$3@lynx.unm.edu>, stephen e buggie
<buggie@ben11.unm.edu> wrote:

> Someone gave me a Mac Plus in mint condition, with 20 meg CMS external
> hard drive.
> 
> I want to copy the contents of the 20 meg HD onto a larger 80 meg HD, then
> put the 80 megger in that external SCSI case.
> 
> The CMS uses DB-25 sockets entirely.   Can I run a 25-to-50 cable from the
> spare socket on the CMS HD, to the receiving SCSI hard drive?   ANy risk
> of damaging anything?   What about SCSI termination???
> 
> Thanks,  Steve Buggie                   buggie@unm.edu

Steve

I acquired one of these last week (20Meg, US power supply) and popped
it open. There appeared to be nothing unusual apart from the use of two
25 pin connectors, rather than the more typical 25/50 pin connector
setup. The SCSI ID on my drive (a Seagate ST225N) is determined by a
DIP switch setup on the rear of the case. You may find that the 80Mb
drive uses a different pin setup for selecting the SCSI ID than the old
20Mb drive so the DIP switches may not work. Just use the standard
jumpers to set the ID directly on the HD which shouldn't be a problem
unless you need to change SCSI ID frequently.

CMS provided a 25 pin connector which had been modified to act as a
SCSI terminator -- this is just a resistor across a couple of pins as I
remember. Anyway, I'm happy to pop the terminator open if needed.

I also connected up the drive to a SCSI Zip drive (to perform a backup)
and there were no problems with connectors or terminators. The previous
owner also used the CMS drive with a Syquest 44Mb cartridge drive
without problem.

Phil